Updated 11 February 2013

Itching

Itching (pruritus) is a sensation on the skin which makes you want to scratch. Itching may be local or generalised (affecting the whole body).

Definition

Itching (pruritus) is a sensation on the skin which makes you want to scratch. Itching may be local or generalised (affecting the whole body). Four types of itch are known according to the site of origin:

Localised – due to local irritation;

Neuropathic – problems with nerves to the skin area;

Neurogenic – originating in the brain; and

Psychogenic – due to a psychological problem.

In all cases, the sensation of itch involves the release of chemicals like histamine in the skin, and/or the processing of nerve signals in the brain. The signals for itch and pain are carried by the same nerve fibres.

Diagnosis

The diagnosis is obvious, but the cause may need investigating. A detailed history of onset, drug use and other symptoms should indicate a cause, but confirmatory tests may be needed.

Blood tests for allergies and infections are useful; chest X-ray may show enlarged glands, and a skin biopsy may give the answer.

Treatment

Because sensations of pain and itch share the same nerve fibres, scratching the affected area, causing mild pain, can act as a counter-irritant. However, excessive scratching can release even more histamine, making matters worse, and may also predispose to skin infections.

Avoid known irritants, such as fabrics or contact allergens (like soaps). Avoid sun exposure, which can trigger or aggravate itch.

Underlying medical conditions contributing to itch (like kidney disease) are managed in their own right.

Topical relief may be had by moisturisers and steroid creams.

Systemic treatment by non-sedating antihistamines is effective. Gabapentin may be tried in uraemic patients who have not responded to other methods.

Get a daily health tip

Stay in touch

The information on Health24 is for educational purposes only, and is not intended as medical advice, diagnosis or treatment. If you are experiencing symptoms or need health advice, please consult a healthcare professional. See additional information.